KR102352267B1 - Device for preheating and heating thick steel for ship using induction heating - Google Patents

Abstract

The present invention relates to an apparatus for preheating and heating a thick steel plate for a ship using induction heating, which increases welding productivity and welding quality of thick steel plates. According to the present invention, the apparatus comprises: a heating pad (11) installed on the upper surface of a thick steel plate (19) and formed of a conductor (12) heated by an induced current generated by electromagnetic induction; an insulation cover (13) installed to surround the heating pad (11) to protect the heating pad (11) from welding heat; a fixing jig (14) installed on both ends and side surfaces of the heating pad (11) to fix the heating pad (11) to the upper surface of the thick steel plate (19); a connector (15) used to interconnect the heating pad (11) and the conductor (12) of the heating pad (11) adjacent to the heating pad (11); a temperature sensor (16) installed to be spaced apart from one side of the plurality of heating pads (11) and measuring the temperature of the thick steel plate (19); a controller (17) controlling the amount of power supplied to the plurality of heating pads (11) by using the temperature data of the thick steel plate (19) received from the temperature sensor (16); and input/output cables (18) connecting the plurality of heating pads (11) and the controller (17).

Description

Device for preheating and heating thick steel for ship using induction heating}

The present invention relates to an apparatus for preheating and heating a thick plate by induction heating, and more particularly, induction for preheating or heating a thick plate using a plurality of heating pads formed of conductors that generate heat by an induced current generated by electromagnetic induction. It relates to a ship preheating and heating device by heating.

As various ships such as container ships and LNG carriers have become larger, the need for welding work for thick plates of 50 mm or more is increasing day by day. In order to improve the productivity of such a welding operation, it is very important to satisfy the welding workability and heat input of the welding material. In addition, in order to improve the welding quality, the preheating operation of the base metal should be preceded before performing the welding operation between the thick plates.

The main purpose of the preheating operation is to raise the temperature of the whole or the vicinity of the joint before welding is performed on materials prone to cold cracking. By reducing the cooling rate of the weld after performing the welding work through the preheating operation, the hardness of the heat-affected zone can be reduced, the toughness can be increased, and the hydrogen emission of the welding part can be facilitated to reduce the quality of the welding material. Cold cracking can be prevented. In addition, it is possible to improve the mechanical properties of the welded portion through the preheating operation, prevent precipitation of hardened tissue, and relieve deformation and residual stress of the welded portion.

For this reason, it is essential to preheat the base material before performing the welding work on the heavy plate, and in some circumstances, it is necessary to perform the heating work on the base material even after the welding work is finished. In order to perform preheating and heating of the heavy plate as described above, a heavy plate preheating and heating device by induction heating is to be applied.

KR 101411853 B1 KR 1019910009397 B1

The present invention has been devised to solve the above problems, and an object of the present invention is to install a plurality of heating pads formed of a conductor that generates heat by an induced current generated by electromagnetic induction on a thick plate using a fixing jig. and to provide a ship preheating and heating apparatus by induction heating, which connects the plurality of heating pads with a connector, and preheats or heats the heavy plate using the plurality of heating pads under the control of a controller.

In order to solve the above technical problems, the ship heavy plate preheating and heating device by induction heating of the present invention is installed on the upper surface of the heavy plate 19, a conductor heated by the induced current generated due to electromagnetic induction ( A heating pad 11 formed of 12), a heat insulating cover 13 installed to surround the heating pad 11 to protect the heating pad 11 from welding heat, both ends and side surfaces of the heating pad 11 is installed in the fixing jig 14 for fixing the heating pad 11 to the upper surface of the heavy plate 19, the heating pad 11 and the conductor 12 of the heating pad 11 adjacent to the heating pad 11 ), a connector 15 used to connect each other, a temperature sensor 16 that is installed to be spaced apart from one side of a plurality of heating pads 11, and measures the temperature of the back plate 19, the temperature sensor 16 A controller 17 for controlling the amount of power supplied to the plurality of heating pads 11 by using the temperature data of the plate 19 received from It is characterized in that it includes an input/output cable (18) for connection.

In addition, in the conductor 12, the conductor 12 is wound several times so that the side surfaces of the conductor 12 do not overlap each other, so that both ends are curved and the opposite sides are formed in the shape of an oval in parallel. do.

In addition, the conductor 12 is characterized in that a tin-plated copper conductor is formed on the inside, and a high heat-resistance silicon insulator is formed on the outside.

In addition, the heat insulating cover 13 is characterized in that the heat-resistant glass fiber fabric coated with a silicone synthetic oil having chemical resistance and insulation properties.

In addition, the temperature sensor 16 is characterized in that it is installed to be spaced 50 ~ 150mm from the side of the heating pad (11).

In addition, the controller 17 includes a setting unit 17a in which a reference power consumption section per unit time is set, an input unit 17b into which actual power consumption data per unit time is input, and the actual consumption per unit time received from the input unit 17b. When the wattage data does not belong to the reference wattage per unit time interval, an alarm is sent to the manager terminal based on the abnormal signal generating unit 17c that generates an abnormal signal and the abnormal signal generated by the abnormal signal generating unit 17c It is characterized in that it includes an alarm unit (17d).

In addition, the reference power consumption per unit time section is a section from a lower limit obtained by subtracting the reference tolerance data from the standard power consumption data per unit time to an upper limit value obtained by adding the reference tolerance data to the reference power consumption data per unit time.

In the vessel preheating and heating device by induction heating of the present invention, a plurality of heating pads formed of a conductor generating heat by an induced current generated due to electromagnetic induction are installed on the plate using a fixing jig, and the plurality of heating By connecting the pads to the connector and directly preheating or heating the thick plate by using the plurality of heating pads under the control of the controller, there is an effect of improving welding productivity and welding quality of the thick plate.

In addition, the vessel preheating and heating device by induction heating of the present invention has the effect of significantly reducing the total amount of power consumed for heating the heavy plate due to the reduction in the heating time of the plate by 50% or more compared to the conventional ceramic heater.

In addition, the vessel preheating and heating apparatus by induction heating of the present invention has the effect of not only heating the heavy plate uniformly using a plurality of heating pads, but also preventing welding cracks caused by hydrogen.

In addition, in the vessel preheating and heating apparatus by induction heating of the present invention, there is no need to heat the heavy plate by using a flame, there is an effect that can create a safe and comfortable welding work environment.

1 is a plan view of a thick plate preheating and heating apparatus by induction heating of the present invention.
2 is a plan view of a case in which the heat insulating cover is removed from the heavy plate preheating and heating apparatus by induction heating of the present invention.
3 is a plan view of the heating pad with the heat insulating cover removed.
4 is a plan view of a heating pad provided with an insulating cover.
5 is a plan view of a heating pad provided with an insulating cover and a fixing jig.
6 is a plan view of the heating pad from which the heat insulating cover is removed according to another embodiment of the present invention.
7 is a plan view of a heating pad provided with a heat insulating cover according to another embodiment of the present invention.
8 is a plan view of a heating pad provided with a heat insulating cover and a fixing jig according to another embodiment of the present invention.
9 is a front view of a controller and an input/output cable.
10 is a block diagram of a controller.
11 is a flowchart illustrating an abnormal situation detection process by a controller.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings in order to describe in detail enough that a person of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention.

However, the following examples are merely examples to help the understanding of the present invention, thereby not reducing or limiting the scope of the present invention. In addition, the present invention may be embodied in several different forms and is not limited to the embodiments described herein.

1 is a plan view of a heavy plate preheating and heating apparatus 10 by induction heating of the present invention, and FIG. 2 is a case in which the insulation cover 13 is removed from the heavy plate preheating and heating apparatus 10 by induction heating of the present invention. is a plan view of

3 is a plan view of the heating pad 11 with the heat insulating cover 13 removed, FIG. 4 is a plan view of the heating pad 11 with the heat insulating cover 13 installed, and FIG. 5 is the heat insulating cover 13 and the fixing jig. It is a plan view of the heating pad 11 provided with (14).

6 is a plan view of the heating pad 11 from which the heat insulating cover 13 is removed according to another embodiment of the present invention, and FIG. 7 is a heating pad 11 provided with the heat insulating cover 13 according to another embodiment of the present invention. ), and FIG. 8 is a plan view of the heating pad 11 provided with the heat insulating cover 13 and the fixing jig 14 according to another embodiment of the present invention.

9 is a front view of the controller 17 and the input/output cable 18 .

10 is a block diagram of the controller 17 .

11 is a flowchart illustrating an abnormal situation detection process by the controller 17 .

First, a description will be given of the ship preheating and heating apparatus 10 by induction heating of the present invention.

1 to 9 , the heavy plate preheating and heating device 10 by induction heating of the present invention includes a heating pad 11 , an insulating cover 13 , a fixing jig 14 , a connector 15 , and a temperature sensor. (16) (not shown) is configured to include a controller 17 and an input/output cable 18 .

First, the heating pad 11 is formed of a conductor 12 heated by an induced current generated due to electromagnetic induction. Specifically, a tin-plated copper conductor is formed on the inside of the conductor 12 of the heating pad 11 , and a high heat-resistance silicon insulator is formed on the outside of the conductor 12 .

In addition, the conductor 12 of the heating pad 11 is formed of a halogen-free eco-friendly material, and can be used in a temperature range of -50 to 200 °C. In addition, the rated voltage and test voltage of the conductor 12 of the heating pad 11 are 250 to 550V and 2500V, respectively, and the breakdown voltage of the conductor 12 of the heating pad 11 is 5500V or more.

Referring to FIGS. 1 and 2 , 8 to 12 heating pads 11 are installed on the upper surface of the thick plate 19 in a rectangular shape to be spaced apart by a predetermined distance in the length and width directions of the thick plate 19 .

3 and 6, the conductor 12 of the heating pad 11 is wound 6 to 12 times so that the side surfaces of the conductor 12 do not overlap each other, so that the shape in which the conductor 12 is wound is curved at both ends, It is formed in the shape of an ellipse in which the side surfaces opposite to each other are parallel. For example, the size of the heating pad 11 is formed to be 1000 (L) X 160 (W) X 18 (T), the width of the heating pad 11 can be changed according to the situation of the field.

3 and 7 , the heat insulating cover 13 is installed in a rectangular shape to surround the outside of the heating pad 11 , and protects the heating pad 11 from welding heat caused by welding between the thick plates 19 . plays a role Here, the heat insulating cover 13 is a heat-resistant glass fiber fabric coated with a silicone synthetic oil having excellent chemical resistance and insulation, and can be used in a temperature range of 500° C. or less.

On the other hand, Teflon-coated sewing machine yarn is used for sewing the fabric constituting the heat insulating cover (13). Here, the Teflon-coated sewing machine yarn is a PTFE (Polytetrafluoroethylene, polytetrafluoroethylene) coated glass fiber thread, which can be used in a temperature range of 540° C. or less.

4 and 8 , the fixing jig 14 is installed on both curved ends and side surfaces of the heating pad 11 , and serves to fix the elliptical heating pad 11 to the upper surface of the heavy plate 19 . do. Here, the fixing jig 14 fixes the heating pad 11 to the upper surface of the thick plate 19 in the shape of a flat plate formed elongated in the longitudinal direction in the form of a straight line or a letter V.

1 and 2 , the connector 15 is used to connect the heating pad 11 and the conductor 12 of the heating pad 11 adjacent to the heating pad 11 to each other. Specifically, the connector 15 connects the heating pad 11 and the conductor 12 of the heating pad 11 adjacent to the heating pad 11 to the heating pad 11 to transmit a current flowing through the heating pad 11 to the heating pad ( 11) and transferred to the adjacent heating pad (11).

And, the temperature sensor 16 is installed to be spaced apart from one side of the plurality of heating pads 11 to measure the temperature of the back plate 19 . Here, the temperature sensor 16 is installed to be spaced 50 ~ 150mm from one side of the plurality of heating pads (11).

Referring to FIG. 9 , the controller 17 controls the amount of power supplied to the plurality of heating pads 11 by using the temperature data of the back plate 19 received from the temperature sensor 16 . Here, the specification of the controller 17 is an input voltage of 380-440V, three-phase, 50Hz, and an output of 30-40KW.

Specifically, in the case of preheating the heavy plate 19 before the welding operation is performed, when the temperature of the thick plate 19 exceeds the target temperature, the controller 17 stops the supply of power to the plurality of heating pads 11 . make it Here, the target temperature of the thick plate 19 is set within the temperature range of 90 ~ 110 ℃.

In addition, when heating the thick plate 19 after the welding operation is completed, if the temperature of the thick plate 19 does not exceed the set temperature within a predetermined time, the controller 17 is supplied to the plurality of heating pads 11 increase the amount of power. And, in the case of heating the thick plate 19 after the welding operation is completed, when the temperature of the thick plate 19 exceeds the set temperature, the controller 17 stops the supply of power to the plurality of heating pads 11 . . Here, the setting temperature of the thick plate 19 is set within the temperature range of 140 ~ 160 ℃.

In addition, the input/output cable 18 is used for connecting the plurality of heating pads 11 and the controller 17 . Here, the length of the input/output cable 18 is 20 m, and the length of the input/output cable 18 may be changed according to the situation of the field.

Meanwhile, referring to FIG. 10 , in the apparatus 10 for preheating and heating a thick plate by induction heating according to the present invention, the controller 17 includes a setting unit 17a, an input unit 17b, and an abnormal signal generating unit 17c and an alarm. and a portion 17d.

First, in the setting unit 17a, a section of the reference power consumption per unit time is set in advance. Here, the reference power consumption per unit time section means a section from the lower limit obtained by subtracting the reference tolerance data from the standard power consumption data per unit time to the upper limit value obtained by adding the reference tolerance data to the standard power consumption data per unit time.

And, in the input unit 17b, actual power consumption data per unit time is input.

And, the abnormal signal generating unit 17c generates an abnormal signal when the actual power consumption data per unit time received from the input unit does not belong to the reference power consumption per unit time interval.

Then, the alarm unit 17c transmits an alarm to the manager terminal based on the abnormal signal generated by the abnormal signal generating unit 17c.

A process in which an abnormal situation is detected by the controller 17 will be described with reference to FIG. 11 .

First, in the setting unit 17a, a section of the reference power consumption per unit time is set.

After that, the data of the actual power consumption per unit time is input to the input unit 17b.

Thereafter, the abnormal signal generating unit 17c generates an abnormal signal when the actual power consumption data per unit time received from the input unit 17b does not belong to the reference power consumption per unit time interval.

Thereafter, the alarm unit 17c transmits an alarm to the manager terminal based on the abnormal signal generated by the abnormal signal generating unit 17c.

Through this process, the manager can immediately determine whether there is an abnormality in the actual power consumption per unit time, and when an abnormal situation actually occurs, corresponding measures can be taken.

Next, a heavy plate preheating by induction heating and a heavy plate 19 preheating test using the heating device 10 of the present invention will be described.

Table 1 shows the conditions of the heavy plate preheating and heating apparatus 10 by induction heating of the present invention for the heavy plate 19 preheating test. Table 1 shows the conditions of the heavy plate preheating by induction heating and the heavy plate 19 preheating test using the heating device 10 of the present invention.

division The details input voltage 380V outside temperature 26℃ target temperature 100℃ plate thickness 38, 50, 90t temperature measurement location from one side of the plurality of heating pads
100mm apart Number of heating pads installed Chapter 12

Referring to Table 1, the temperature of the back plate 19 was measured from the temperature sensor 16 installed to be 100 mm apart from one side of the plurality of heating pads 11 . In this test, the target temperature of the heavy plate 19 is 100° C., and the number of heating pads 11 installed on the upper surface of the thick plate 19 is 12 in total.

Table 2 is a table comparing the time to reach the target temperature of 100 ℃ for each thickness of the thick plate 19 in the heavy plate 19 preheating test using the heavy plate preheating and heating device 10 by induction heating of the present invention. Table 2 shows the preheating test results of the heavy plate 19 using the heavy plate preheating and heating device 10 by induction heating of the present invention.

thickness of plate Time to reach target temperature 100℃ 38t 50 minutes 50t 72 minutes 90t 83 minutes

Referring to Table 2, when the thickness of the thick plate 19 installed on the heating pad 11 is increased, the temperature increase rate of the thick plate 19 is reduced. And, when the number of heating pads 11 installed on the thick plate 19 is reduced, the temperature increase rate of the thick plate 19 is increased. And, when the input voltage by the controller 17 rises, the temperature rise rate of the thick plate 19 increases. In addition, the time to reach the target temperature of the heating pad 11 varies according to the temperature measurement position by the temperature sensor 16 .

Next, a preheating test of the heavy plate preheating and heating device 10 by induction heating of the present invention and the thick plate 19 using the conventional ceramic heater was compared.

Table 3 is a table comparing the preheating test of the heavy plate by the induction heating apparatus 10 of the present invention and the thick plate 19 by the conventional ceramic heater.

Item Heavy plate preheating and heating device by induction heating Conventional Ceramic Heater note Power Consumption 5KW/1m heater 10KW/1m heater 50% compared to the previous heating time 25 minutes (1m, 20℃ → 150℃) 30 minutes (1m, 20℃ → 150℃) 83% compared to the previous Power consumption when heating 1.25KWh (1m, 150℃) 5KWh (1m, 150℃) 25% compared to the previous Power consumption during preheating 30KWh (6m, 1hr) 60KWh (6m, 1hr) 50% compared to the previous equipment installation time 0.25MH (1unit) 3.0MH(1unit) 8.3% compared to the previous equipment removal time 0.25MH (1unit) 1.5MH (1unit) 16.6% compared to the previous safety - No significant risk due to limited temperature rise of heavy plate - Risk of burns when touched due to the heat of the heater itself Installation/operation
Precautions - No overlapping installation
- Somewhat irrelevant to the close contact with the conductor
- No need to keep warm - Possible to decrease thermal efficiency
- Closely installed on the conductor
- Required to keep warm

Referring to Table 3, in the heavy plate preheating and heating apparatus 10 by induction heating of the present invention, the power consumption, heating time, heating power consumption and preheating power consumption are 50% and 83%, respectively, compared to conventional ceramic heaters. , it can be seen that the reduction was reduced to 25% and 50%. In addition, it can be seen that in the heavy plate preheating and heating apparatus 10 by induction heating of the present invention, the equipment installation time and the equipment removal time are reduced by 8.3% and 16.6%, respectively, compared to the conventional ceramic heater.

Next, electricity consumption was compared when the thick plate preheating and heating device 10 by induction heating of the present invention and the conventional ceramic heater were respectively applied to solid lines.

This test was conducted on welding work for a 4,000TEU container ship. And, in this test, a total welding length of 18,000 m, 6 m preheating per one time, and a total of 3,000 preheating conditions were applied. And, in this test, the industrial electricity rate was applied at 90 won/KWh.

Table 4 is a table comparing electricity consumption when the thick plate preheating and heating device 10 and the conventional ceramic heater by induction heating of the present invention are applied to the solid lines, respectively.

Item Heavy plate preheating and heating device by induction heating Conventional ceramic heater note total heating time 1,260 hours 1,500 hours 50% compared to the previous warm-up time 6,000 hours 6,000 hours existing same assumption Total power consumption during heating 22,500KWh 90,000KWh 25% compared to the previous Total power consumption during preheating 180,000KWh 360,000KWh 50% compared to the previous Total power consumption 202,500KWh 450,000KWh 45% compared to the previous Electricity bill 18,225,000 won KRW 40,500,000 45% compared to the previous

Referring to Table 4, when the thick plate preheating and heating device 10 by induction heating of the present invention is applied to a solid line, the total power consumption and electricity cost will be reduced by 247,500 KWh and 22 million won per unit, respectively, compared to the conventional ceramic heater. is expected to

In the apparatus for preheating and heating a thick plate by induction heating of the present invention, a plurality of heating pads formed of a conductor generating heat by an induced current generated by electromagnetic induction are installed on the thick plate using a fixing jig, and the plurality of heating pads is connected to the connector, and by directly preheating or heating the thick plate using the plurality of heating pads under the control of the controller, there is an advantage in that welding productivity and welding quality of the thick plate can be improved.

In addition, the heavy plate preheating and heating apparatus by induction heating of the present invention has an advantage in that the total amount of power consumed for heating the thick plate is significantly reduced because the heating time of the thick plate is reduced by 50% or more compared to the conventional ceramic heater.

In addition, the apparatus for preheating and heating a heavy plate by induction heating of the present invention has the advantage of being able to uniformly heat the thick plate by using a plurality of heating pads, as well as preventing welding cracks caused by hydrogen.

In addition, in the heavy plate preheating and heating apparatus by induction heating of the present invention, there is no need to heat the thick plate using a flame, there is an advantage that can create a safe and comfortable welding work environment.

As described above, the present invention has a main technical idea to provide a heavy plate preheating and heating device by induction heating, and the embodiment described above with reference to the drawings is only one embodiment, and the true right of the present invention The scope is based on the claims, but will also extend to equivalent embodiments that may exist in various ways.

10: Thick plate preheating and heating device by induction heating of the present invention
11: heating pad 12: conductor
13: insulation cover 14: fixing jig
15: connector 16: temperature sensor
17: controller 17a: setting unit
17b: input unit 17c: abnormal signal generation unit
17d: alarm unit 18: input/output cable
19: plate

Claims (7)

a heating pad 11 formed of a conductor 12 installed on the upper surface of the thick plate 19 and heated by an induced current generated due to electromagnetic induction;
an insulating cover 13 installed to surround the heating pad 11 to protect the heating pad 11 from welding heat;
a fixing jig 14 installed on both ends and side surfaces of the heating pad 11 to fix the heating pad 11 to the upper surface of the back plate 19;
a connector 15 used to connect the heating pad 11 and a conductor 12 of the heating pad 11 adjacent to the heating pad 11 to each other;
a temperature sensor 16 that is installed to be spaced apart from one side of the plurality of heating pads 11 and measures the temperature of the back plate 19;
a controller 17 for controlling the amount of power supplied to the plurality of heating pads 11 by using the temperature data of the back plate 19 received from the temperature sensor 16; and
Including a; input/output cable (18) for connecting the plurality of heating pads (11) and the controller (17);
The conductor 12 is
The conductor 12 is wound several times so that the side surfaces of the conductor 12 do not overlap each other, so that both ends are bent and the opposite sides are formed in the shape of an oval in parallel,
The conductor 12 is
A tin-plated copper conductor is formed on the inside, and a high heat-resistant silicone insulator is formed on the outside,
The heat insulating cover 13 is
It is a heat-resistant glass fiber fabric coated with a silicone synthetic oil having chemical resistance and insulation,
In the heat insulating cover 13
Teflon-coated sewing machine yarn is used for sewing the fabric constituting the heat insulation cover 13,
The Teflon coating sewing machine is
PTFE (Polytetrafluoroethylene, polytetrafluoroethylene) coated glass fiber thread, which can be used in the temperature range below 540℃,
The controller 17 is
In the case of preheating the thick plate 19 before the welding operation is performed, when the temperature of the thick plate 19 exceeds the target temperature, the supply of power to the plurality of heating pads 11 is stopped,
The target temperature is
It is set within the temperature range of 90 ~ 110 ℃,
The controller 17 is
When the heavy plate 19 is heated after the welding operation is completed, if the temperature of the thick plate 19 does not exceed the set temperature within a predetermined time, the amount of power supplied to the plurality of heating pads 11 is increased and ,
When the heavy plate 19 is heated after the welding operation is completed, when the temperature of the thick plate 19 exceeds the set temperature, the supply of power to the plurality of heating pads 11 is stopped,
The setting temperature is set within the temperature range of 140 ~ 160 ℃,
The controller 17 is
a setting unit (17a) in which a reference power consumption section per unit time is set;
an input unit 17b to which actual power consumption data per unit time is input;
an abnormal signal generating unit 17c that generates an abnormal signal when the actual power consumption data per unit time received from the input unit 17b does not belong to the reference power consumption per unit time interval; and
Including;;
The standard power consumption per unit time section is
Heavy plate preheating and heating device for ships by induction heating, characterized in that it is a section from the lower limit obtained by subtracting the reference tolerance data from the standard power consumption data per unit time to the upper limit value obtained by adding the reference tolerance data to the standard power consumption data per unit time. delete delete delete delete delete delete

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